Data transmission system, data recording and reproducing apparatus and recording medium each having data structure of error correcting code

ABSTRACT

A data transmission system for transmitting information data with a parity of an error correcting code for correcting an error in the information data. A read-out controller controls a transmitter to transmit information data and a parity so that each data component of the information data obtained by dividing the information data of one data block area into a plurality of data components and each parity component of the parity obtained by dividing the parity of one block area into a plurality of parity components are transmitted at intervals of each sector having a sector address. The sector is defined as an data area obtained by dividing one data block area of a predetermined data amount into a plurality of sectors each having an identical data amount.

CROSS REFERENCE TO RELATED APPLICATIONS

The present application is a continuation-in-part of pending U.S. patentapplication Ser. No. 08/626,547, filed on Apr. 2, 1996, now abandoned,in the name of S. TANAKA et al. entitled "Data Transmission System, DataRecording And Reproducing Apparatus And Recording Medium Each HavingData Structure Of Error Correcting Code". The disclosure of U.S. patentapplication Ser. No. 08/626,547 is expressly incorporated by reference,in its entirety, herein.

BACKGROUND OF THE INVENTION

1. Field of the Invention

The present invention relates to a data transmission system, a datarecording and reproducing apparatus, and a recording medium each havinga data structure of error correcting code, a data structure for use in arecording medium, a method for arranging a parity of an error correctioncode, a method for transmitting information data, a method for receivinginformation data, a method for recording information data in a recordingmedium, and a method for reproducing information data from a recordingmedium.

In particular, the present invention relates to a data transmissionsystem for transmitting data through a communication line, a datarecording and reproducing apparatus for recording data into a recordingmedium and reproducing data from the recording medium, and a recordingmedium such as an optical disk, a magneto-optical disk, a magnetic disk,a compact disk, a magnetic tape, a semiconductor memory, or the like,each of the data transmission system, the data recording and reproducingapparatus, and the recording medium having a data structure of errorcorrecting code, a data structure for use in a recording medium, amethod for arranging a parity of an error correcting code, a method fortransmitting information data, a method for receiving information data,a method for recording information data in a recording medium, and amethod for reproducing information data from a recording medium.

2. Description of the Prior Art

When transmitting and recording a great amount of digital data, an errorcorrecting code (referred to as an ECC hereinafter) is widely used forthe purpose of improving the reliability of the data.

The ECC word generated by attaching a parity to an original data, andthen, the redundancy of the data having the parity increases, however,the ECC has the capabilities of detecting and correcting errorsgenerated in the process of transmitting, recording and reproducing thedata.

In general, the ECC has a higher error correcting capability when theECC word has an increased redundancy, i.e., when the ECC word includes agreater amount of parity symbols. Therefore, the ECC word includes aplurality of parity symbols or bytes.

Conventionally, when ECC encoding a great amount of data upontransmitting or recording the data, the data is previously divided intoa plurality of blocks each having a predetermined length, and a parityis attached to each block. Then, the parity is arranged at the tail ofthe block to be corrected, generally. That is, in the conventionalprocess of data transmission, the data has been transmitted with theparity added to the tail of each data block. On the other hand, in thedata recording process, the parity has been recorded in a positionadjacent to each data block.

An arrangement of the data and the parity of the ECC word in theconventional data recording method is concretely shown in FIG. 1.

FIG. 1 shows a logical data format of one block of an optical disk inwhich data and a parity are recorded by a prior art method for arrangingthe parity of the ECC.

The block is divided into a data area 90, a row parity area 54, and acolumn parity area 53, depending on the type of information datarecorded. In the present case, the parity is a part of the ECC word. Asis apparent from FIG. 1, the row parity area 54 and the column parityarea 53 are partially overlapped with each other.

One block is comprised of 156 data frames 51 and 12 parity frames. Inthe present case, the frame 51 means a group of data or paritiescorresponding to one row of each block, and constructs an ECC word inthe row direction.

Each data frame 51 is comprised of data of 158 bytes and a row parity of10 symbols each of which consists of one byte (referred to as a C1parity hereinafter) for error correction of the data. Then, thirteendata frames constitute one sector 52. Therefore, one block is comprisedof twelve sectors 52 in this case. At the head of each sector 52 iswritten a physical sector address 50 of each sector 52 (referred to as asector address hereinafter). Further, it is noted that a synchronous(Sync) pattern (not shown) is generally added to the head of each frame.

In the column parity 53, twelve bytes in the direction of columnconstitute one parity (referred to as a C2 parity hereinafter), and theparity is used for correcting an error of the 156-byte data serieslocated upward in an identical column. The above-mentioned 156-byte dataand 12-byte parity construct an ECC word in the column direction. FIG. 1shows a logical format of one block, and the block is physically writtencontinuously in a sequence from the frame located in the uppermostposition of the block onto a track of an optical disk in a manner asshown in FIG. 2. Therefore, paying attention to the data series in thedirection of column, data are discretely arranged on the disk, and thisarrangement is referred to as an interleave.

Thus, conventionally, in both of (a) the data arrangement in thedirection of row, i.e., the data series which is not interleaved and (b)the data arrangement in the direction of column, i.e., the data serieswhich is interleaved, the data area 90 in which data is arranged and theparity area 91 in which the parity is arranged have been clearlydistinguished from each other.

However, according to the recent trend of increasing the storagecapacities and reducing the access times of optical disks, upon readingout data from any optical disk in which the data have been written bythe prior art arrangement method, there have been such problems asfollows.

Attention is now paid to timings for detecting sector addresses uponcontinuously reading out information along a track. FIG. 3 shows thetimings for the above operation. In this case, the information data issequentially read out from the frame located in the uppermost positionof the block shown in FIG. 1, and therefore, the twelve sector addressesare detected at a predetermined regular time interval. However, sincethe twelve column parity frames of the column parity 53 are subsequentlyread out, and therefore, a certain time interval continues for which nosector address is detected continues. Thereafter, the next block is readout, and then, the similar phenomenon occurs repetitively.

Thus, according to the conventional method for arranging the parity ofthe ECC, the timings for detecting the sector addresses becomesirregular. Therefore, upon retrieving a desired sector address, acomplicated control circuit and a complicated calculator circuit arenecessary, and this leads to a cause of retarding the time ofreading-out. In this case, for example, by providing only the row paritywithout adding the column parity itself, the timings for detecting thesector addresses can be made regular. However, with only the row parity,the data correcting capability is reduced to impair the reliability ofthe recorded data.

SUMMARY OF THE INVENTION

A first object of the present invention is therefore to provide a datatransmission system comprising a data transmitter and a data receiver,said system being capable of regularly transmitting information data ina data area, and regularly receiving the information data arrangedregularly in the data area without impairing the reliability of thetransmitted data.

A second object of the present invention is to provide a data recordingand reproducing apparatus comprising a data recorder and a datareproducer, said apparatus being capable of regularly recording orwriting information data in a data area, and regularly reproducing orreading-out the information data arranged regularly in the data areawithout impairing the reliability of the recorded data.

A third object of the present invention is to provide a recordingmedium, in which information data can be regularly recorded or writtenin a data area, and the recorded information data regularly arrangedregularly in the data area can be reproduced or read out withoutimpairing the reliability of the recorded data.

A fourth object of the present invention is to provide a data structurefor use in a recording medium, in which information data can beregularly recorded or written in a data area, and the recordedinformation data regularly arranged regularly in the data area can bereproduced or read out without impairing the reliability of the recordeddata.

A fifth object of the present invention is to provide a method forarranging a parity of an ECC, by which information data can be regularlyrecorded or written in a data area, and the recorded information dataregularly arranged regularly in the data area can be reproduced or readout without impairing the reliability of the recorded data.

A sixth object of the present invention is to provide a method fortransmitting information data, capable of regularly transmittinginformation data in a data area.

A seventh object of the present invention is to provide a method forreceiving information data, capable of regularly receiving informationdata arranged regularly in the data area without impairing thereliability of the transmitted data.

An eighth object of the present invention is to provide a method forrecording information data, capable of regularly recording or writinginformation data in a data area of a recording medium.

A ninth object of the present invention is to provide a method forreproducing information data, capable of regularly reproducing orreading out information data arranged regularly in the data area of therecording medium without impairing the reliability of the transmitteddata.

In order to achieve the above-mentioned objective, according to a firstaspect of the present invention, there is provided a data transmissionsystem for transmitting information data with a parity of an errorcorrecting code for correcting an error in the information data,comprising a data transmitter and a data receiver,

wherein said data transmitter comprises:

first storage means for storing information data to be transmitted;

second storage means for storing a parity of an error correcting code;

write control means for writing input information data to be transmittedinto said first storage means;

parity generating means for generating a parity to form an errorcorrecting code word of an error correcting code for correcting an errorof the information data using a predetermined error correcting codingmethod in response to the information data stored in said first storagemeans, and writing the parity into said second storage means;

transmitting means for transmitting the information data stored in saidfirst storage means together with the parity stored in said secondstorage means; and

read-out control means for controlling said transmitting means totransmit the information data stored in said first storage means and theparity stored in said second storage means so that each data componentof the information data obtained by dividing the information data of onedata block area into a plurality of data components and each paritycomponent of the parity obtained by dividing the parity of one blockarea into a plurality of parity components are transmitted at intervalsof each sector having a sector address, said sector being defined as andata area obtained by dividing one data block area of a predetermineddata amount into a plurality of sectors each having an identical dataamount,

wherein data receiver comprises:

receiving means for receiving each data component of the informationdata and each parity component of the parity which are transmitted atintervals of each sector by said transmitting means;

data extracting means for extracting the information data of one blockarea by combining a plurality of data components received by saidreceiving means;

parity extracting means for extracting the parity of one block area bycombining a plurality of parity components received by said receivingmeans; and

error correcting means for correcting an error in the information dataof one block area extracted by said data extracting means, using apredetermined error correcting decoding method, based on the parity ofone block area extracted by said parity extracting means, and outputtingan error-corrected information data.

In the above-mentioned data transmission system, the parity preferablyincludes a row parity and a column parity, and each sector is comprisedof a plurality of frames,

wherein said read-out control means controls said transmitting means totransmit the row parity at the tail of each frame after each datacomponent, and the column parity in the last frame of each sector.

According to a second aspect of the present invention, there is provideda data transmitter for transmitting information data with a parity of anerror correcting code for correcting an error in the information data,comprising:

first storage means for storing information data to be transmitted;

second storage means for storing a parity of an error correcting code;

write control means for writing input information data to be transmittedinto said first storage means;

parity generating means for generating a parity to form an errorcorrecting code word of an error correcting code for correcting an errorof the information data using a predetermined error correcting codingmethod in response to the information data stored in said first storagemeans, and writing the parity into said second storage means;

transmitting means for transmitting the information data stored in saidfirst storage means together with the parity stored in said secondstorage means; and

read-out control means for controlling said transmitting means totransmit the information data stored in said first storage means and theparity stored in said second storage means so that each data componentof the information data obtained by dividing the information data of onedata block area into a plurality of data components and each paritycomponent of the parity obtained by dividing the parity of one blockarea into a plurality of parity components are transmitted at intervalsof each sector having a sector address, said sector being defined as andata area obtained by dividing one data block area of a predetermineddata amount into a plurality of sectors each having an identical dataamount.

In the above-mentioned data transmitter, the parity preferably includesa row parity and a column parity, and each sector is comprised of aplurality of frames,

wherein said read-out control means controls said transmitting means totransmit the row parity at the tail of each frame after each datacomponent, and the column parity in the last frame of each sector.

According to a third aspect of the present invention, there is provideda data receiver for receiving information data with a parity of an errorcorrecting code for correcting an error in the information data,comprising:

receiving means for receiving each data component of the informationdata and each parity component of the parity which are transmitted atintervals of each sector;

data extracting means for extracting the information data of one blockarea by combining a plurality of data components received by saidreceiving means;

parity extracting means for extracting the parity of one block area bycombining a plurality of parity components received by said receivingmeans; and

error correcting means for correcting an error in the information dataof one block area extracted by said data extracting means, using apredetermined error correcting decoding method, based on the parity ofone block area extracted by said parity extracting means, and outputtingan error-corrected information data.

According to a fourth aspect of the present invention, there is provideda data recording and reproducing apparatus for recording informationdata with a parity of an error correcting code for correcting an errorin the information data into a recording medium, and reproducing theinformation data with the parity from said recording medium, comprisinga data recorder and a data reproducer,

wherein said data recorder comprises:

first storage means for storing information data to be recorded;

second storage means for storing a parity of an error correcting code;

write control means for writing input information data to be recordedinto said first storage means;

parity generating means for generating a parity to form an errorcorrecting code word of an error correcting code for correcting an errorof the information data using a predetermined error correcting codingmethod in response to the information data stored in said first storagemeans, and writing the parity into said second storage means;

recording means for recording into said recording medium, theinformation data stored in said first storage means together with theparity stored in said second storage means; and

read-out control means for controlling said recording means to recordthe information data stored in said first storage means and the paritystored in said second storage means so that each data component of theinformation data obtained by dividing the information data of one datablock area into a plurality of data components and each parity componentof the parity obtained by dividing the parity of one block area into aplurality of parity components are recorded at intervals of each sectorhaving a sector address, said sector being defined as an data areaobtained by dividing one data block area of a predetermined data amountinto a plurality of sectors each having an identical data amount,

wherein data reproducer comprises:

reproducing means for reproducing each data component of the informationdata and each parity component of the parity which are recorded atintervals of each sector in said recording medium;

data extracting means for extracting the information data of one blockarea by combining a plurality of data components reproduced by saidreproducing means;

parity extracting means for extracting the parity of one block area bycombining a plurality of parity components reproduced by saidreproducing means; and

error correcting means for correcting an error in the information dataof one block area extracted by said data extracting means, using apredetermined error correcting decoding method, based on the parity ofone block area extracted by said parity extracting means, and outputtingan error-corrected information data.

In the above-mentioned apparatus, the parity preferably includes a rowparity and a column parity, and each sector is comprised of a pluralityof frames,

wherein said read-out control means controls said recording means torecord the row parity at the tail of each frame after each datacomponent, and the column parity in the last frame of each sector.

According to a fifth aspect of the present invention, there is provideda data recorder for recording information data with a parity of an errorcorrecting code for correcting an error in the information data into arecording medium, comprising:

first storage means for storing information data to be recorded;

second storage means for storing a parity of an error correcting code;

write control means for writing input information data to be recordedinto said first storage means;

parity generating means for generating a parity to form an errorcorrecting word of an error correcting code for correcting an error ofthe information data using a predetermined error correcting codingmethod in response to the information data stored in said first storagemeans, and writing the parity into said second storage means;

recording means for recording into said recording medium, theinformation data stored in said first storage means together with theparity stored in said second storage means; and

read-out control means for controlling said recording means to recordthe information data stored in said first storage means and the paritystored in said second storage means so that each data component of theinformation data obtained by dividing the information data of one datablock area into a plurality of data components and each parity componentof the parity obtained by dividing the parity of one block area into aplurality of parity components are recorded at intervals of each sectorhaving a sector address, said sector being defined as an data areaobtained by dividing one data block area of a predetermined data amountinto a plurality of sectors each having an identical data amount.

In the above-mentioned data recorder, the parity preferably includes arow parity and a column parity, and each sector is comprised of aplurality of frames,

wherein said read-out control means controls said recording means torecord the row parity at the tail of each frame after each datacomponent, and the column parity in the last frame of each sector.

According to a sixth aspect of the present invention, there is provideda data reproducer for reproducing information data with a parity of anerror correcting code from a recording medium, comprising:

reproducing means for reproducing each data component of the informationdata and each parity component of the parity which are recorded atintervals of each sector in said recording medium;

data extracting means for extracting the information data of one blockarea by combining a plurality of data components reproduced by saidreproducing means;

parity extracting means for extracting the parity of one block area bycombining a plurality of parity components reproduced by saidreproducing means; and

error correcting means for correcting an error in the information dataof one block area extracted by said data extracting means, using apredetermined error correcting decoding method, based on the parity ofone block area extracted by said parity extracting means, and outputtingan error-corrected information data.

According to a seventh aspect of the present invention, there isprovided a recording medium having a data structure of information dataand a parity of an error correcting code for correcting an error in theinformation data, said recording medium being usable by a datareproducer,

said recording medium comprising:

data reproducer readable information data; and

data reproducer readable parity of an error correcting code,

wherein each data component of the information data obtained by dividingthe information data of one data block area into a plurality of datacomponents and each parity component of the parity obtained by dividingthe parity of one block area into a plurality of parity components arerecorded at intervals of each sector having a sector address, saidsector being defined as an data area obtained by dividing one data blockarea of a predetermined data amount into a plurality of sectors eachhaving an identical data amount.

In the above-mentioned recording medium, the parity preferably includesa row parity and a column parity, and each sector is comprised of aplurality of frames,

wherein the row parity is recorded at the tail of each frame after eachdata component, and the column parity is recorded in the last frame ofeach sector.

According to an eighth aspect of the present invention, there isprovided a data structure for use in a recording medium havinginformation data and a parity of an error correcting code for correctingan error in the information data, said recording medium being usable bya data reproducer,

said data structure comprising:

data reproducer readable information data; and

data reproducer readable parity of an error correcting code,

wherein each data component of the information data obtained by dividingthe information data of one data block area into a plurality of datacomponents and each parity component of the parity obtained by dividingthe parity of one block area into a plurality of parity components arerecorded at intervals of each sector having a sector address, saidsector being defined as an data area obtained by dividing one data blockarea of a predetermined data amount into a plurality of sectors eachhaving an identical data amount.

In the above-mentioned data structure, the parity preferably includes arow parity and a column parity, and each sector is comprised of aplurality of frames,

wherein the row parity is recorded at the tail of each frame after eachdata component, and the column parity is recorded in the last frame ofeach sector.

According to a ninth aspect of the present invention, there is provideda method for arranging a parity of an error correcting code forcorrecting an error in the information data, in a recording medium,including the following step of:

arranging the information data and the parity so that each datacomponent of the information data obtained by dividing the informationdata of one data block area into a plurality of data components and eachparity component of the parity obtained by dividing the parity of oneblock area into a plurality of parity components are recorded atintervals of each sector having a sector address, said sector beingdefined as an data area obtained by dividing one data block area of apredetermined data amount into a plurality of sectors each having anidentical data amount.

In the above-mentioned method, the parity preferably includes a rowparity and a column parity, and each sector is comprised of a pluralityof frames,

wherein said arranging step includes the step of arranging the rowparity at the tail of each frame after each data component, and thecolumn parity in the last frame of each sector.

According to a tenth aspect of the present invention, there is provideda method for transmitting information data with a parity of an errorcorrecting code for correcting an error in the information data,including the following steps of:

writing input information data to be transmitted into first storagemeans;

generating a parity to form an error correcting code word of an errorcorrecting code for correcting an error of the information data using apredetermined error correcting coding method in response to theinformation data stored in said first storage means, and writing theparity into said second storage means;

transmitting the information data stored in said first storage meanstogether with the parity stored in said second storage means; and

controlling to transmit the information data stored in said firststorage means and the parity stored in said second storage means so thateach data component of the information data obtained by dividing theinformation data of one data block area into a plurality of datacomponents and each parity component of the parity obtained by dividingthe parity of one block area into a plurality of parity components aretransmitted at intervals of each sector having a sector address, saidsector being defined as an data area obtained by dividing one data blockarea of a predetermined data amount into a plurality of sectors eachhaving an identical data amount.

In the above-mentioned method, the parity preferably includes a rowparity and a column parity, and each sector is comprised of a pluralityof frames,

wherein said controlling step includes the step of controlling totransmit the row parity at the tail of each frame after each datacomponent, and the column parity in the last frame of each sector.

According to an eleventh aspect of the present invention, there isprovided a method for receiving information data with a parity of anerror correcting code for correcting an error in the information data,including the following steps of:

receiving each data component of the information data and each paritycomponent of the parity which are transmitted at intervals of eachsector;

extracting the information data of one block area by combining aplurality of received data components;

extracting the parity of one block area by combining a plurality ofreceived parity components; and

correcting an error in the information data of one block area extracted,using a predetermined error correcting decoding method, based on theparity of one block area extracted, and outputting an error-correctedinformation data.

According to a twelfth aspect of the present invention, there isprovided a method for recording information data with a parity of anerror correcting code for correcting an error in the information datainto a recording medium, including the following steps of:

writing input information data to be recorded into first storage means;

generating a parity to form an error correcting code word of an errorcorrecting code for correcting an error of the information data using apredetermined error correcting coding method in response to theinformation data stored in said first storage means, and writing theparity into second storage means;

recording into said recording medium, the information data stored insaid first storage means together with the parity stored in said secondstorage means; and

controlling to record the information data stored in said first storagemeans and the parity stored in said second storage means so that eachdata component of the information data obtained by dividing theinformation data of one data block area into a plurality of datacomponents and each parity component of the parity obtained by dividingthe parity of one block area into a plurality of parity components arerecorded at intervals of each sector having a sector address, saidsector being defined as an data area obtained by dividing one data blockarea of a predetermined data amount into a plurality of sectors eachhaving an identical data amount.

In the above-mentioned method, the parity preferably includes a rowparity and a column parity, and each sector is comprised of a pluralityof frames,

wherein said controlling step includes the step of controlling to recordthe row parity at the tail of each frame after each data component, andthe column parity in the last frame of each sector.

According to a thirteenth aspect of the present invention, there isprovided a method for reproducing information data with a parity of anerror correcting code from a recording medium, including the followingsteps of:

reproducing each data component of the information data and each paritycomponent of the parity which are recorded at intervals of each sectorin said recording medium;

extracting the information data of one block area by combining aplurality of data components reproduced;

extracting the parity of one block area by combining a plurality ofparity components reproduced; and

correcting an error in the information data of one block area extracted,using a predetermined error correcting decoding method, based on theparity of one block area extracted, and outputting an error-correctedinformation data.

According to the present invention, a parity is not recorded in abunched continuous area but recorded dispersedly in each sectors of theareas in which the data to be corrected is recorded. Therefore, theinformation data arranged regularly in the data area is regularly readout, thereby producing such an advantageous effect that the datareproducing or read-out apparatus is allowed to be simplified andimproved for higher operation speed.

Further, according to the present invention, the parity is not solelytransmitted continuously but transmitted in such a manner that it isdispersedly mixed with the data to be corrected. The above arrangementproduces such an advantageous effect that the information data arrangedregularly in the data area can be transmitted at a predeterminedconstant time interval.

Furthermore, according to the present invention, when interleaved symboldata or ECC block data is received, the data series and the parity arereproduced from the symbol data or ECC block data, so that the errorgenerated in the data series is corrected. Therefore, when the parity isdispersedly transmitted, the data series and the parity are easilyrecognized, thereby producing such an advantageous effect that the errorgenerated in the data series is corrected.

BRIEF DESCRIPTION OF THE DRAWINGS

These and other objects and features of the present invention willbecome clear from the following description taken in conjunction withthe preferred embodiments thereof with reference to the accompanyingdrawings throughout which like parts are designated by like referencenumerals, and in which:

FIG. 1 is a schematic diagram showing a logical data format of one blockof an optical disk in which a parity of an ECC is recorded by a priorart method for arranging a parity of an ECC word;

FIG. 2 is a schematic plan view showing a frame and a sector written ona track of a prior art optical disk;

FIG. 3 is a timing chart showing timings for detecting sector addresseswhen reading out the prior art optical disk shown in FIGS. 1 and 2;

FIG. 4 is a schematic diagram showing a logical data format of one blockof an optical disk of a recording medium of a first preferred embodimentaccording to the present invention;

FIG. 5 is a schematic diagram showing a logical data format of a headerwritten in the optical disk of the recording medium shown in FIG. 4;

FIG. 6 is a timing chart showing timings for detecting sector addressesin the first preferred embodiment;

FIG. 7 is a schematic plan view showing a read only optical disk inwhich the parity is written by the method for arranging the parity ofthe ECC of the first preferred embodiment;

FIG. 8 is a schematic plan view showing a rewritable optical disk inwhich the parity is written by the method for arranging the parity of anECC of the first preferred embodiment;

FIG. 9 is a block diagram showing a composition of a data transmissionsystem of a second preferred embodiment according to the presentinvention;

FIG. 10 is a block diagram showing a composition of a data transmittershown in FIG. 9;

FIG. 11 is a block diagram showing a composition of a data receivershown in FIG. 9;

FIG. 12 is a flowchart showing a process of a memory write controllershown in FIG. 10;

FIG. 13 is a flowchart showing a first part of a process of a paritygenerator shown in FIG. 10;

FIG. 14 is a flowchart showing a second part of the process of theparity generator shown in FIG. 10;

FIG. 15 is a flowchart showing a process of a memory read-out controllershown in FIG. 10;

FIG. 16 is a flowchart showing a first part of a process of a datareceiver shown in FIG. 11;

FIG. 17 is a flowchart showing a second part of the process of the datareceiver shown in FIG. 11;

FIG. 18 is a block diagram showing a composition of a phase-change typeoptical disk recording and reproducing apparatus of a third preferredembodiment according to the present invention;

FIG. 19 is a flowchart showing a first part of a process of the paritygenerator shown in FIG. 10, according to a fourth embodiment of thepresent invention; and

FIG. 20 is a flowchart showing a process of the memory read-outcontroller shown in FIG. 10, according to the fourth embodiment.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

Preferred embodiments according to the present invention will bedescribed in detail hereinafter with reference to the attached drawings.

First preferred embodiment

As a first preferred embodiment, an exemplified recording medium inwhich a parity of an ECC is dispersedly recorded is shown.

FIG. 4 shows a logical data format of one block of an optical disk inwhich ECC words are recorded by a method for arranging a parity of theECC of the first preferred embodiment according to the presentinvention.

As is apparent from comparison between FIGS. 1 and 4, this logical dataformat is characterized in that the parity of the ECC includes rowparities 24-1 to 24-13 and a pair of column parities 23a and 23b isrecorded in each of sectors 22-1 to 22-16, each of the row parities 24-1to 24-13 is arranged in the tail of each of rows or frames 21-1 to21-13, and a pair of column parities 23-1a and 23-1b is arranged in thelast frame 21-13 of each of the sectors 22-1 to 22-16.

The logical data format of a data structure shown in FIG. 4 will bedescribed in detail below.

Referring to FIG. 4, 1-block data to be transmitted is comprised of 16sectors 22-1 to 22-16, and each of the sectors 22-1 to 22-16 iscomprised of 13 rows, namely, 13 frames 21-1 to 21-13. For synchronoustransmission, a first synchronous (Sync) pattern 31 of 2 bytes is addedto a part prior to the head of each of the frames 21-1 to 21-13, and asecond synchronous (Sync) pattern 32 of 2 bytes is inserted into themiddle part of each of the frames 21-1 to 21-13 so as to be arrangedbetween adjacent two information data 1a and 1b, 2a and 2b, . . . , 12aand 12b, or adjacent column parities 23a and 23b. In the preferredembodiments, an ECC word of the ECC in each of the frames 21-1 to 21-13is constituted so as to exclude the first and second synchronouspatterns 31 and 32.

The first sector 22-1 is comprised of 13 frames 21-1 to 21-13, in which,

(a) the first frame 21-1 includes a header 20 of 12 bytes, theinformation data 1a of 79 bytes, the information data 1b of 81 bytes,and a row parity 24-1 of 10 bytes which is calculated based on theheader 20 and the information data 1a and 1b;

(b) the second frame 21-2 includes information data 2a of 91 bytes,information data 2b of 81 bytes, and a row parity 24-2 of 10 bytes whichis calculated based on the information data 2a and 2b;

(c) the I-th frame 21-I includes information data ia of 91 bytes,information data ib of 81 bytes, and a row parity 24-I of 10 bytes whichis calculated based on the information data ia and ib, (I=3, 4, . . . ,11);

(d) the 12-th frame 21-12 includes information data ia of 91 bytes,information data 12b of 77 bytes, an error detection code (EDC) 25 of 4bytes for the header 20 and information data 1a, 1b, 2a, 2b, . . . , 12aand 12b, and a row parity 24-12 of 10 bytes which is calculated based onthe information data 12a and 12b, and the error detection code 25; and

(e) the 13-th frame 21-13 includes a column parity 23a of 91 bytes, acolumn parity 23b of 81 bytes, and a row parity 24-13 of 10 bytes whichis calculated based on the column parities 23a and 23b.

Further, each of the second to 16-th sectors 22-2 to 22-16 is comprisedof 13 frames 21-1 to 21-13, in a manner similar to that of the firstsectors 22-1. In the ECC block data consisting of the sectors 22-1 to22-16, the column parities 23a are calculated based on all the headers20, all the information data 1a, 2a, 3a, . . . , and 12a, and the columnparities 23b are calculated based on all the information data 1b, 2b,3b, . . . , and 12b, and all the error detection codes (EDC) 25. Each ofthe row parities 14-1 to 14-13 are calculated based on the rest of eachof the rows or frames 21-1 to 21-13. Furthermore, the row parities 24-13of all sectors 22-1 to 22-16 can be also be calculated in the mass basedon a set of the row parities 24-1 to 24-12 of all the sectors 22-1 to22-16.

FIG. 5 shows a logical data format of a header written in the opticaldisk shown in FIG. 4.

Referring to FIG. 5, the header 20 arranged at the head of each of thesectors 22-1 to 22-16 includes a sector address 61 of 4 bytes, an errorcorrection code (IEC) of 2 bytes for sector address 61, and an attributedata 63 of 6 bytes for representing an attribute of the sector 22.Therefore, one sector address 61 is arranged at the head of each of thesectors 22-1 to 22-16.

In this case, if attention is paid to the information data and parity ofone column of one bytes, one column parity of 16 bytes for correcting anerror of (12×16)-byte data of one column is arranged uniformly in thecolumn so as to be segmented into 16 column parities each of one byte.That is, the format shown in FIG. 4 differs from the format of FIG. 1 inthe location of the column parities 23a and 23b of the 16 sectors ifthey are compared from each other, and the relation between each parityand series of correction of the data format of the first preferredembodiment shown in FIG. 4 is substantially the same as that of priorart shown in FIG. 1.

Now, attention is paid to timings for detecting the sector addresses 61when the information data is continuously read out along the track ofthe optical disk in which the column parities 23a and 23b of the 16sectors 22-1 to 22-16 are dispersedly recorded as described above.

FIG. 4 shows the logical format of one block, and the block isphysically recorded continuously in sequence from the uppermost framealong the track of the disk, and in each frame, each data is recordedsequentially from the leftmost byte to the rightmost byte. This is thesame as that of the prior art optical disk shown in FIG. 2.

FIG. 6 is a timing chart showing timings for detecting sector addressesin the first preferred embodiment.

As shown in FIG. 6, the sector addresses 61 are detected regularly at apredetermined constant time interval Tc even in the detection of thesector addresses 61 performed in the boundary from the current block tothe next block. As is apparent from the data format shown in FIG. 4,each sector address 61 is detected once in thirteen frames, and this isthe same when the read-out process continues to the next block.

FIG. 7 is a schematic plan view showing a read only optical disk 3001 inwhich the parity of the ECC is written by the method for arranging theparity of the ECC of the first preferred embodiment.

Referring to FIG. 7, a recording area is arranged in a spiral shape, andone sector 22 is arranged into a part of a spiral recording area of theread only optical disk 3001 having a center hole 3001h. That is, a CLV(Constant Linear Velocity) method is used as a recording method for theread only optical disk 3001. Further, as is apparent from FIG. 7, eachsector address 61 of the header 20 is detected at the predeterminedconstant time interval Tc in the read only optical disk 3001.

FIG. 8 is a schematic plan view showing a rewritable optical disk 3002in which the parity of the ECC is written by the method for arrangingthe parity of the ECC of the first preferred embodiment.

Referring to FIG. 8, a recording area is arranged in a spiral shape, andone sector 22 is arranged into a part of one turn of an recording areaof the rewritable optical disk 3002 having a center hole 3002h. That is,a zoned CAV (Constant Angular Velocity) method is used as a recordingmethod for the rewritable optical disk 3002. Further, as is apparentfrom FIG. 8, each sector address 61 of the header 20 is detected at thepredetermined constant time interval Tc in the rewritable optical disk3002.

As is apparent from the above description of the first preferredembodiment, each sector address 61 of the header 20 is detected at thepredetermined constant time interval Tc in the optical disk 3001 or 3002of the recording medium of the present preferred embodiment in a mannerdifferent from that of the case of the prior art shown in FIG. 1. In thepresent case, data to be regularly detected is of course not limited tothe sector address. For example, the data to be regularly detected maybe the header 20. That is, data arranged so as to be interleaved incorresponding positions in an identical column or frame 21 of each ofthe sectors 22 is guaranteed to be surely detected at the predeterminedconstant time interval Tc.

Second preferred embodiment

As a second preferred embodiment, an exemplified data transmissionsystem for dispersedly transmitting a parity of an ECC is shown.

FIG. 9 is a block diagram showing a composition of a data transmissionsystem of a second preferred embodiment according to the presentinvention.

Referring to FIG. 9, the data transmission system comprises a datatransmitter 1000 and a data receiver 2000. Input data is inputted to amemory write controller 101, and then, the input data is processed inthe data transmitter 1000 in a manner as described in detail later.Thereafter, a transmitted signal including the input data and a parityof an ECC is transmitted from a transmitter 106 through a telephone line4000 to a receiver 201 of the data receiver 2000. The transmitted signalis received by the receiver 201, and then is processed in the datareceiver 2000 in a manner as described in detail later. Then, outputdata is outputted from an error correcting processor 205 of the datareceiver 2000.

FIG. 10 is a block diagram showing a composition of the data transmitter1000 shown in FIG. 9. It is to be noted that FIG. 10 includes conceptualdiagrams of not only data 108 and 109 stored respectively in a datamemory 102 and a parity memory 104, but also data 107 and 110 flowingthrough the respective paths for the sake of better perception andbetter understanding.

The data transmitter 1000 comprises the memory write controller 101, thedata memory 102, a parity generator 103 having an ECC encoder 103a, theparity memory 104, a memory read-out controller 105 and the transmitter106. In the data transmitter 1000, the memory write controller 101comprises a page counter 121 and a data counter 122, and the paritygenerator 103 comprises a page counter 123 and a data counter 124.

The memory write controller 101 comprises the page counter 121 forcounting a page number corresponding to a block number and the datacounter 122 for counting a row number j in byte and a column number i inbyte, and latches or temporarily stores the input data sent from anexternal unit, then stores the input data into the data memory 102having a memory capacity of two pages (pages "0" and "1") correspondingto two blocks, based on the numbers i, j and p indicated by the page anddata counters 121 and 122. The data transmission system manages data ofN rows×M columns as one block, and transmits data in a unit of one blockwith a parity attached thereto. In the second preferred embodiment, N is(12×16) frames, and M is 182 bytes except for synchronous patterns 31and 32, as is apparent from FIG. 4. Therefore, the memory writecontroller 101 latches the input data 107 of N rows×M columns as a unitor one block, from the external unit.

The parity generator 103 comprises the ECC encoder 103a inside thereof,and the page counter 123 for counting a page number corresponding to ablock number and a data counter 124 for counting a row number j in byteand a column number i in byte. The parity generator 103 calculates aparity for the information data 108 of N rows×M columns stored in thedata memory 102, using, for example, the Reed-Solomon coding methodwhich has been already known to those skilled in the art. In practice,the parity generator 103 calculates the row parity 24 comprised of mbytes for correcting an error of the row ECC word of each row comprisedof M bytes of data and m-byte row parity. In the preferred embodiment, mis 10 bytes as is apparent from FIG. 4. Furthermore, in the direction ofcolumn, the parity generator 103 similarly calculates the column parity23a or 23b comprised of n bytes for correcting an error of the columnECC word series of each column comprised of N bytes of data and n-bytesof the column parity 23a or 23b. In the preferred embodiment, n is 16bytes, as is apparent from FIG. 4.

The parity data 109 calculated by the parity generator 103 is storedinto the parity memory 104. The data memory 102 and the parity memory104 are provided in different blocks with regard to the type of theinformation data stored in each of the memories 102 and 103, however,they are practically allocated to areas of different addresses in a RAMcomprised of a semiconductor memory or the like.

The memory read-out controller 105 reads out the information data 108 ofN rows×M columns stored in the data memory 102 and the parity 109 storedin the parity memory 104 according to a predetermined procedure, andtransmits to the transmitter 106 the information data 108 and paritydata 109 as a transmission data or an ECC block data 110 in which theinformation data of one block and the parity are mixed together. It isto be noted that the transmission data 110 has the same format as thatof FIG. 4 described in the first preferred embodiment.

Therefore, the symbol data or ECC block data is sent by the memoryread-out controller 105 so that the row parity 24 and the columnparities 23a and 23b are sent at intervals of each sector 22, whereinthe sector 22 is defined as an data area obtained by dividing one datablock area of a predetermined data amount into a plurality of sectors 22each having an identical data amount, or as a part of the transmitteddata for transmitting information data of a predetermined amountincluding the EDC 25. Hereinafter, the data including the informationdata 108 and the parity data 109 is referred to as an ECC block data110.

The transmitter 106 comprises a modulator and an amplifier. Thetransmitter 106 modulates a carrier signal according to the transmissionECC block data 110 including the information data 108 and the paritydata 109 which is sent from the memory read-out controller 105, using apredetermined digital modulation method such as FSK, PSK, QAM or thelike, then amplifies the modulated transmitted signal, and transmits thetransmitted signal through the telephone line 4000 of a public switchedtelephone network to the receiver 201 of the data receiver 2000 as shownin FIG. 9.

In the preferred embodiment, the read-out controller 105 controls thetransmitter 106 to transmit the information data stored in the datamemory 102, and the row parities 24 and the column parities 23a and 23bstored in the parity memory 104 so that each data component of theinformation data obtained by dividing the information data of one datablock area into a plurality of data components and each parity componentof the row parities 24 and the column parities 23a and 23b obtained bydividing the row parities 24 and the column parities 23a and 23b of oneblock area into a plurality of parity components are transmitted atintervals of each sector 22.

In the preferred embodiment, the parity of the ECC includes row parities24 and column parities 23a and 23b, and each sector 22 is comprised of aplurality of frames 21. The read-out controller 105 controls thetransmitter 106 to transmit the row parity 24 at the tail of each frame21 after each data component, and the column parities 23a and 23b in thelast frame 21 of each sector 22.

FIG. 11 is a block diagram showing a composition of the data receiver2000 shown in FIG. 9. It is to be noted that FIG. 11 includes conceptualdiagrams of data 207 and 208 stored respectively in a data memory 203mand a parity memory 204m and data 206 flowing through each path for thesake of better perception and better understanding.

The data receiver 2000 comprises the receiver 201, a memory writecontroller 201a, an ECC block data memory 202, a data extractor 203, aparity data extractor 204, the data memory 203m, the parity memory 204m,and the error correcting processor 205. In the data receiver 2000, thememory write controller 201a comprises a page counter 221 for counting apage number corresponding to a block number and a data counter 222 forcounting a row number j in byte and a column number i in byte, and theparity extractor 204 comprises an ECC decoder 204a inside thereof.

The receiver 201 comprises a telephone receiver and a demodulator, andreceives a received signal including the ECC block data 110 of FIG. 10which is sent from the data transmitter 1000, then demodulates themodulated signal of the received signal using a predetermineddemodulation method corresponding to the modulation method used in thetransmitter 106 shown in FIG. 10 so as to generate received dataincluding the ECC block data 110, which is sent to the memory writecontroller 201a. The memory write controller 201a stores the input datainto the ECC block data memory 202 based on the numbers p, i and jindicated by the page and data counters 221 and 222. In the presentcase, it is assumed that the received data 206 is comprised of data of(N+n) rows×(M+m) columns and parities having a data structure shown inFIG. 4. In the preferred embodiment, the information data and the parityare represented by symbols each of one byte. It is to be noted that theECC block data memory 202 has a storage capacity of to two pages (pages"0" and "1") corresponding to two blocks, in a manner similar to that ofthe data memory 102 shown in FIG. 10.

The data extractor 203 extracts and reads out only the information data207 from the received ECC block data 206 stored in the ECC block datamemory 202, and then transmits the extracted data 207 to the errorcorrecting processor 205 through the data memory 203m of a data buffermemory. In other words, the data extractor 203 extracts the informationdata of one block area by combining a plurality of data components, asshown in 207 of FIG. 11.

On the other hand, the parity data extractor 204 extracts and reads outonly the parity 208 from the received ECC block data 206 stored in theECC block data memory 202, and then transmits the parity 208 to theerror correcting processor 205 through the parity memory 204m of aparity buffer memory. In other words, the parity data extractor 204extracts the parity of one block area by combining a plurality of paritycomponents, as shown in 208 of FIG. 11.

The error correcting processor 205 executes a predetermined calculatingprocess by means of the information data 207 transmitted from the dataextractor 203 and the parity 208 transmitted from the parity dataextractor 204, and then outputs the resulting data whose errors havebeen corrected as output data. In other words, the error correctingprocessor 205 corrects an error in the information data of the ECC wordof one block area extracted by the data extractor 203 and the parityextractor 204, using a predetermined error correcting decoding methodcorresponding to the error correcting encoding method of the datatransmitter 1000, based on the parity of the ECC extracted by the parityextractor 204, and outputs an error-corrected information data.

The operation of the data transmission system comprising the datatransmitter 1000 and the data receiver 2000 constructed as above will bedescribed below with reference to FIGS. 10 to 17.

FIG. 12 is a flowchart showing a process of the memory write controller101 which obtains and latches the input data 107 of N rows×M columns. Inthe present case, the data memory 102 has a storage capacity of a totalof two pages (pages "0" and "1"), where the information data of N rows×Mcolumns corresponds to one page. The page counter 121 shown in FIG. 10serves to perform a buffering process with switching between two pagesfor storing input data in steps S401 and S410 to S412. Each one-byteinput data is stored into the data memory 102 sequentially from the leftside to the right side in each row or frame in steps S403 to S407 andsequentially from the uppermost row or frame to the lowermost row orframe in steps S408 to S409.

FIGS. 13 and 14 are flowcharts showing a process of the parity generator103 of FIG. 10 for calculating the parity. In the present case, the ECCencoder 103a is provided inside the parity generator 103, and has thefollowing structure: when plural-bytes data is inputted into the ECCencoder 103a one-byte by one-byte, calculation is performed by the ECCencoder 103a one byte by one byte.

When the information data of one row or frame stored in the data memory102 is read out by repeatedly reading out one-byte data from the datamemory 102 and one row parity 24 of ten bytes for one frame iscalculated in steps S501 to S505, the one row parity 24 of ten bytes forone frame is stored in the position of the row parity 24 of the paritymemory 104 in steps S506 to S510. Thereafter, according to a similarprocedure, data in the column direction is read out by repeatedlyreading out one-byte data from the data memory 102 and 16-byte paritysymbols on the column in the column parities 23a or 23b, or the last rowparity 24-13 of each sector 22 are calculated in steps S511 to S515, andthen, the parity symbols of the column parities 23a or 23b, or the lastrow parity 24-13 of each sector 22 are stored in the position of thecolumn parities of the parity memory 104 in steps S516 to S520. Thisprocedure is repeated until the rightmost column in step S521 to S523.

FIG. 15 is a flowchart showing a process of the memory read-outcontroller 105 of FIG. 10. A read-out output sequence is indicated inthe transmitted ECC block data 110 of FIG. 10, where data of one row orframe including the row parity 24 is sequentially read out from itsuppermost row or frame, and then is transmitted to the transmitter 106in steps S601 to S607. It is to be noted that one row parity frame orthe last frame including the column parities 23a and 23b and the rowparity 24-13 is read out every time Q data frames are read out in stepsS608 to S614. By this operation, the frames 21-13 of the column parities23a and 23b are dispersedly transmitted from the transmitter 106. Thecase where the information data is read out from the data memory 102 instep S606 and the case where the parity is read out from the paritymemory 104 in step S612 are not necessary to be specificallydistinguished from each other in the flowchart of FIG. 15. Because theyare merely located in different addresses of one storage area inpractice.

As is apparent from the above description, the input data 107 of Nrows×M columns obtained by the memory write controller 101 is processedby the data transmitter 1000 so as to attach the parity 109 to theinformation data, and the parity 109 is transmitted from the transmitter106 dispersedly in the form of interleaved data in the column direction.

FIGS. 16 and 17 are flowcharts showing a process of the data receiver2000 for executing an error correcting process by obtaining the receiveddata 206 comprised of symbols of (N+n) rows×(M+m) columns.

In the present case, the ECC decoder 204a is provided inside the parityextractor 204, and has the following structure: when plural-bytes datais inputted into the ECC decoder 204a one-byte by one-byte, thecalculation is executed one-byte by one-byte by the ECC decoder 204a.

When receiving the ECC word of one frame, the error correcting processis executed in the row direction in steps S801 to S809. This process isrepeated for all the frames in steps S810 to S811. When the errorcorrecting process in the row direction is completed, subsequently theerror correcting process in the row direction is executed according to asimilar procedure in steps S818 to S825. When the error correctingprocess of the ECC words or ECC block data corresponding to one page iscompleted through the above-mentioned process, then, the same errorcorrecting process is repeated for the symbol stored in another page ofthe ECC block data memory 202 in steps S826 to S828.

As is apparent from the above description, the symbols of (N+n)rows×(M+m) columns obtained by the receiver 201 are subjected to theerror correcting process in the data receiver 2000, and then, theerror-corrected data of (N rows)×(M columns) is outputted from the errorcorrecting processor 205.

Third preferred embodiment

FIG. 18 is a block diagram showing a composition of a phase-change typeoptical disk recording and reproducing apparatus of a third preferredembodiment according to the present invention.

As is apparent from comparison between FIGS. 9 and 18, the differencesbetween the second and third preferred embodiments are as follows:

(1) a recording processor 16a is provided in stead of the transmitter106;

(2) a reproducing processor 201a is provided in stead of the receiver201; and

(3) a disk driving mechanism 112 for rotating the disk 3000, laserdiodes 111 and 211 and a photo detector 212 are further provided to thesecond preferred embodiment shown in FIG. 9.

In response to the input data with the parity sent from the memoryread-out controller 105, the recording processor 106a converts the inputdata into a recording signal, amplifies the recording signal, and thenoutputs the amplified recording signal to the laser diode 111. The laserdiode 111 generates laser light modulated according to the recordingsignal for recording and projects the laser light onto a part of thedisk 3000 to be recorded. On the other hand, the laser diode 211generates a relatively weak continuous laser light for reproducing andprojects the laser light onto a part of the disk 3000 to be reproduced,and then, a reflected light on the part of the disk 3000 is incidentonto the photo detector 212 which detects the reflected light, convertsthe same into an electric signal, and outputs the electric signal to thereproducing processor 201a. The reproducing processor 201a performs awaveform-shaping process so as to convert the input electric signal intoa pulse-shaped digital data.

In the optical disk 3000, an optical recording layer is formed, in whicha first reflectance represents information data "0", and a secondreflectance represents information data "1".

Upon recording of information data "0" or "1", the laser light of afirst intensity or a second intensity is respectively projected from thelaser diode 111 onto a part of the disk 3000 to be recorded. Then, thereflectance of the recording layer becomes a first value or a secondvalue according to the intensity of the laser light.

On the other hand, upon reading-out of information data, the weak laserlight is continuously projected from the laser light 211 onto a part ofthe disk 3000 to be reproduced, and then a value, e.g. an intensity ofthe reflected light is detected by the photo detector 212.

In the third preferred embodiment, the rewritable disk 3000 is used,however, the present invention is not limited to this. The presentinvention can be applied to the other kind of disk recording andreproducing apparatus, such as a read only optical disk, an additionalrecordable disk or the like.

Fourth preferred embodiment

FIGS. 19 and 20 illustrate a fourth preferred embodiment of the secondpreferred embodiment.

FIG. 19 is a variation of the operations illustrated in FIG. 13 that areperformed by parity generator 103. Similarly, FIG. 20 is a variation ofthe operations illustrated in FIG. 15 that are performed by the memoryreadout controller 105. Accordingly, the following discussion will belimited to the operations that differ from the second preferredembodiment.

The process of the parity generator 103 in the fourth preferredembodiment that differs from the second preferred embodiment will now bedescribed. As illustrated in FIG. 19, step S506 is executed when thedetermination at step S502 is negative, and after the execution of stepS510. In step S506, a determination is made as to whether the columnnumber i is less than the sum of the column M and row parity m. If thedetermination is affirmative, the process proceeds to step S507, as inthe second preferred embodiment. However, if the determination isnegative, the process proceeds to execute steps S530, S531 and S532.

In step S530, the row number j is incremented by 1. Thereafter, the rownumber j is compared to the row N in step S531. When the row number j isless than the row N, the process proceeds to step S532, in order toreset the column number i to 0, before returning to step S502.

On the other hand, when it is determined (in step S531) that the row Nis larger than or equal to the row number j, the process proceeds tostep S511, illustrated in FIG. 14, in order to execute steps S511 toS523.

According to this embodiment, when the information data of one row orframe stored in the data memory 102 is read out by repeatedly readingout one-byte data from the data memory 102 and one row parity 24 of tenbytes for one frame is calculated in steps S501 to S505, the one rowparity 24 of ten bytes for one frame is stored in the position of therow parity 24 of the parity memory 104 in steps S506 to S510. Thisprocedure is repeated on every row through steps S530 to S532.Thereafter, processing of the fourth preferred embodiments proceeds asillustrated in FIG. 14.

Specifically, data in the column direction is read out by repeatedlyreading out one-byte data from the data memory 102 and sixteen-byteparity symbols on the column in the column parities 23a or 23b, or thelast row parity 24-13 of each sector 22 are calculated in steps S511 toS515. Thereafter, the parity symbols of the column parities 23a or 23b,or the last row parity 24-13 of each sector 22 are stored in theposition of the column parities of the parity memory 104 in steps S516to S520. This procedure is repeated on every column through steps S521to S523.

The process of the memory read-out controller in the fourth preferredembodiment that differs from the second preferred embodiment will now bedescribed. As illustrated in FIG. 20, data of one row (or frame)including the row parity 24 is sequentially read out from its uppermostrow (or frame), and is transmitted to the transmitter 106 (see FIG. 10)in steps S601 to S607. One row parity frame or the last frame includingthe column parities 23a and 23b, and the row parity 24-13 is read outevery time Q data frames are read out in steps S608 to S614. Thus,frames 21-13 of the column parities 23a and 23b are dispersedlytransmitted from the transmitter 106.

In this regard, when it is determined at step S609 that mod(j,Q) is notequal to 0, processing returns to step S602. Similarly, after step S614is executed, processing returns to step S602. Thus, the process cyclesthrough steps S602 to S614 until the row number j is equal to or largerthan row N.

Other embodiments

The method for arranging the parity of the ECC of the present inventionhas been described based on the preferred embodiments thereof, however,the present invention is of course not limited to those preferredembodiments. The following other embodiments may be provided.

In the first preferred embodiment, the column parity comprised of 16bytes is arranged dispersedly one byte by one byte. However, the presentinvention is not limited to such numerical specifications. For example,there may be adopted a method for dispersedly arranging a column paritycomprised of 48 bytes three bytes by three bytes.

In the second preferred embodiment, the parity generator 103 and thememory read-out controller 105 are operated after the information dataof one block has been entirely inputted to the memory write controller101. However, the present invention is not limited to such a sequence.For example, just after the memory write controller 101 has obtained theinformation data of one row, the parity generator 103 may calculate therow parity of the information data.

In the above-mentioned preferred embodiments, the optical disk is usedas a recording medium, however, the present invention is not limited tothis. The present invention can be applied to the other kind ofrecording medium, such as a magneto-optical disk, an optical disk, amagnetic disk, a compact disk, a magnetic tape, a semiconductor memory,or the like.

In the above-mentioned preferred embodiments, the telephone line 4000 isused, however, the present invention is not limited to this. The otherkind of communication line can be used such as an ISDN (IntegratedServices Digital Network) line, a packet exchange network line, an ATM(Asynchronous Transfer Mode) communication line, a Frame Relaycommunication line, or the like.

In the above-mentioned preferred embodiments, the parity of theReed-Solomon code of the forward error correction method is used as theECC, however, the present invention is not limited this. For example, ablock code such as a Hamming code, an extended Hamming code, a BCH(Bose-Chau-dri-Hockengem) code, a Fire code or the like may be used asthe ECC.

In the above-mentioned preferred embodiments, the data structure shownin FIG. 4 is used, however, the present invention is not limited tothis. A data structure similar to that shown in FIG. 4 may be used inwhich the sector addresses 50 are arranged at each sector so that thesector addresses 50 can be detected at a predetermined constant timeinterval.

Although the present invention has been fully described in connectionwith the preferred embodiments thereof with reference to theaccompanying drawings, it is to be noted that various changes andmodifications are apparent to those skilled in the art. Such changes andmodifications are to be understood as included within the scope of thepresent invention as defined by the appended claims unless they departtherefrom.

What is claimed is:
 1. A data transmission system for transmittinginformation data with a parity of an error correcting code forcorrecting an error in said information data, comprising a datatransmitter and a data receiver,wherein said data transmittercomprises:a first storage device that stores information data to betransmitted; a second storage device that stores a parity of an errorcorrecting code; a write control device that writes input informationdata to be transmitted to said first storage device; a parity generatingdevice that generates a parity to form an error correcting code word ofan error correcting code to correct an error of said information datausing a predetermined error correcting coding method in response to saidinformation data stored in said first storage device, and writing theparity to said second storage device; a transmitting device thattransmits said information data stored in said first storage device andsaid parity stored in said second storage device; and a read-out controldevice that controls said transmitting device to transmit saidinformation data stored in said first storage device and said paritystored in said second storage device, so that each data component ofsaid information data, obtained by dividing said information data of onedata block area into a plurality of data components, and each paritycomponent of said parity, obtained by dividing said parity of one blockarea into a plurality of parity components, are transmitted at intervalsof each sector having a sector address, so that said plurality of paritycomponents are dispersedly arranged in one block to be transmitted, saidsector being defined as a data area obtained by dividing one data blockarea of a predetermined data amount into a plurality of sectors, eachhaving an identical data amount, and wherein said data receivercomprises:a receiving device that receives each data component of saidinformation data and each parity component of said parity transmitted atintervals of each sector by said transmitting device; a data extractingdevice that extracts said information data of one block area bycombining a plurality of data components received by said receivingdevice; a parity extracting device that extracts said parity of oneblock area by combining a plurality of parity components received bysaid receiving device; and an error correcting device that corrects anerror in said information data of one block area extracted by said dataextracting device, using a predetermined error correcting decodingmethod, based on said parity of one block area extracted by said parityextracting device, and outputting an error-corrected information data,wherein the parity includes a row parity and a column parity, and eachsector is comprised of a plurality of frames, and wherein said read-outcontrol device controls said transmitting device to transmit the rowparity at the tail of each frame after each data component, and thecolumn parity in the last frame of each sector.
 2. A data transmitterfor transmitting information data with a parity of an error correctingcode for correcting an error in said information data, comprising:afirst storage device that stores information data to be transmitted; asecond storage device that stores a parity of an error correcting code;a write control device that writes input information data to betransmitted to said first storage device; a parity generating devicethat generates a parity to form an error correcting code word of anerror correcting code that corrects an error of said information datausing a predetermined error correcting coding method in response to saidinformation data stored in said first storage device, and writing theparity to said second storage device; a transmitting device thattransmits information data stored in said first storage device saidparity stored in said second storage device; and a read-out controldevice that controls said transmitting device to transmit saidinformation data stored in said first storage device and said paritystored in said second storage device so that each data component of saidinformation data, obtained by dividing said information data of one datablock area into a plurality of data components, and each paritycomponent of said parity, obtained by dividing said parity of one blockarea into a plurality of parity components, are transmitted at intervalsof each sector having a sector address, so that said plurality of paritycomponents are dispersedly arranged in one block to be transmitted, saidsector being defined as a data area obtained by dividing one data blockarea of a predetermined data amount into a plurality of sectors, eachhaving an identical data amount, wherein the parity includes a rowparity and a column parity, and each sector is comprised of a pluralityof frames, and wherein said read-out control device controls saidtransmitting device to transmit the row parity at the tail of each frameafter each data component, and the column parity in the last frame ofeach sector.
 3. A data recording and reproducing apparatus for recordinginformation data with a parity of an error correcting code forcorrecting an error in said information data into a recording medium,and reproducing said information data with said parity from saidrecording medium, comprising a data recorder and a datareproducer,wherein said data recorder comprises:a first storage devicethat stores information data to be recorded; a second storage devicethat stores a parity of an error correcting code; a write control devicethat writes input information data to be recorded into said firststorage device; a parity generating device that generates a parity toform an error correcting code word of an error correcting code tocorrect an error of said information data using a predetermined errorcorrecting coding method in response to said information data stored insaid first storage device, and writing said parity into said secondstorage device; a recording device that records, to said recordingmedium, said information data, stored in said first storage device, andsaid parity, stored in said second storage device; and a read-outcontrol device that controls said recording device to record saidinformation data stored in said first storage device and said paritystored in said second storage device so that each data component of saidinformation data, obtained by dividing information data of one datablock area into a plurality of data components, and each paritycomponent of said parity, obtained by dividing said parity of one blockarea into a plurality of parity components, are recorded at intervals ofeach sector having a sector address, so that said plurality of paritycomponents are dispersedly arranged in one block to be transmitted, saidsector being defined as a data area obtained by dividing one data blockarea of a predetermined data amount into a plurality of sectors eachhaving an identical data amount, wherein data reproducer comprises:areproducing device that reproduces each data component of saidinformation data and each parity component of said parity which arerecorded at intervals of each sector in said recording medium; a dataextracting device that extracts information data of one block area bycombining a plurality of data components reproduced by said reproducingdevice; a parity extracting device that extracts said parity of oneblock area by combining a plurality of parity components reproduced bysaid reproducing device; and an error correcting device that corrects anerror in said information data of one block area extracted by said dataextracting device, using a predetermined error correcting decodingmethod, based on said parity of one block area extracted by said parityextracting device, and outputting an error-corrected information data,wherein the parity includes a row parity and a column parity, and eachsector is comprised of a plurality of frames, and wherein said read-outcontrol device controls said recording device to record the row parityat the tail of each frame after each data component, and the columnparity in the last frame of each sector.
 4. A data recorder forrecording information data with a parity of an error correcting code forcorrecting an error in said information data into a recording medium,comprising:a first storage device that stores information data to berecorded; a second storage device that stores a parity of an errorcorrecting code; a write control device that writes input informationdata to be recorded to said first storage device; a parity generatingdevice that generates a parity to form an error correcting word of anerror correcting code to correct an error of said information data usinga predetermined error correcting coding method in response to saidinformation data stored in said first storage device, and writing saidparity to said second storage device; a recording device that records,to said recording medium, said information data stored in said firststorage device and said parity stored in said second storage device; anda read-out control device that controls said recording device to recordsaid information data stored in said first storage device and saidparity stored in said second storage device, so that each data componentof said information data, obtained by dividing said information data ofone data block area into a plurality of data components, and each paritycomponent of said parity, obtained by dividing said parity of one blockarea into a plurality of parity components, are recorded at intervals ofeach sector having a sector address, said sector being defined as andata area obtained by dividing one data block area of a predetermineddata amount into a plurality of sectors each having an identical dataamount, wherein the parity is dispersedly arranged in each sector,wherein the parity includes a row parity and a column parity, and eachsector is comprised of a plurality of frames, and wherein said read-outcontrol device controls said recording device to record the row parityat the tail of each frame after each data component, and the columnparity in the last frame of each sector.
 5. A method for arranging aparity of an error correcting code for correcting an error in aninformation data, in a recording medium, comprising:arranging theinformation data and a parity so that each data component of theinformation data, obtained by dividing the information data of one datablock area into a plurality of data components, and each paritycomponent of the parity, obtained by dividing the parity of one blockarea into a plurality of parity components, are recorded at intervals ofeach sector having a sector address such that the parity is dispersedlyarranged in each sector, the sector being defined as an data areaobtained by dividing one data block area of a predetermined data amountinto a plurality of sectors, each having an identical data amount,wherein the parity includes a row parity and a column parity, eachsector comprising a plurality of frames, and wherein the arranging ofthe information data and the parity comprises arranging the row parityat a tail of each frame after each data component, and arranging acolumn parity in a last frame of each sector.
 6. A method fortransmitting information data with a parity of an error correcting codefor correcting an error in the information data, comprising:writinginput information data to be transmitted into a first storage device;generating a parity to form an error correcting code word of an errorcorrecting code to correct an error of the information data using apredetermined error correcting code method in response to theinformation data stored in said first storage device, and writing theparity into a second storage device; transmitting the information data,stored in the first storage device, and the parity, stored in the secondstorage device; and controlling the transmitting of the information dataand the parity so that each data component of the information data,obtained by dividing the information data of one data block area into aplurality of data components, and each parity component of the parity,obtained by dividing the parity of one block area into a plurality ofparity components, are transmitted at intervals of each sector having asector address such that the parity is dispersedly arranged in eachsector, the sector being defined as a data area obtained by dividing onedata block area of a predetermined data amount into a plurality ofsectors, each sector having an identical data amount, wherein the parityincludes a row parity and a column parity, each sector comprising aplurality of frames, and wherein the controlling of the transmitting ofinformation data and the parity comprises controlling a transmission ofthe row parity to be at a tail of each frame after each data component,and controlling a transmission of a column parity to be in a last frameof each sector.
 7. A method for recording information data with a parityof an error correcting code for correcting an error in the informationdata recorded to a recording medium, comprising:writing inputinformation data, to be recorded, to a first storage device; generatinga parity to form an error correcting code word of an error correctingcode to correct an error of the information data using a predeterminederror correcting coding method in response to the information datastored in the first storage device, and writing the parity to a secondstorage device; recording the information data, stored in the firststorage device, and the parity, stored in the second storage device, tothe recording medium; and controlling the recording of the informationdata and the parity so that each data component of the information data,obtained by dividing the information data of one data block area into aplurality of data components, and each parity component of the parity,obtained by dividing the parity of one block area into a plurality ofparity components, are recorded at intervals of each sector having asector address such that the parity is dispersedly arranged, the sectorbeing defined as a data area obtained by dividing one data block area ofa predetermined data amount into a plurality of sectors, each sectorhaving an identical data amount, wherein the parity includes a rowparity and a column parity, each sector comprising a plurality offrames, and wherein the controlling of the recording of the informationdata and the parity comprises controlling a recording of the row parityto be at a tail of each frame after each data component, and controllinga recording of a column parity to be in a last frame of each sector.